export class MassStorageDevice {
  public _file = null as any;
  public _size = null as any;
  public _state = null as any;
  public _zeroOffset = null as any;
  public _owner;
  public STATE_NOTPRESENT = 0;
  public STATE_CHANGE = 2;
  public STATE_READY = 3;
  public STATE_NOTREADY = 4;
  public STATE_BAD = 5;
  public _reader = null as any;
  public vm: any;
  constructor(owner: any, file: any, vm:any) {
    this._owner = owner;
    this.vm = vm;
    this._Init(file);
  }

  isEject() {
    if (this._state === this.STATE_READY) {
      return false;
    } else {
      return true;
    }
  }

  _Init(file: any) {
    if (file) {
      this._file = file;
      this._size = file.size;
      this._state = this.STATE_NOTPRESENT;
      this._zeroOffset = 0;
    } else {
      this._file = null;
      this._size = -1;
      this._zeroOffset = 0;
      return;
    }

    const blob = this._file.slice(0, 512);
    this._reader = new FileReader();
    const self = this;
    this._reader.onload = function (e: any) {
      const head = new Uint8Array(e.target.result);
      if (
        head[0] === 67 &&
        head[1] === 80 &&
        head[2] === 81 &&
        head[3] === 82 &&
        head[4] === 70 &&
        head[5] === 66 &&
        head[6] === 76 &&
        head[7] === 79
      ) {
        this._zeroOffset = (head[14] & 0xff) | (head[15] << 8);
      }
    };
    this._reader.readAsArrayBuffer(blob);
  }

  GetDeviceSize() {
    if (this._state === this.STATE_READY) {
      return this._size - this._zeroOffset;
    } else {
      return -1;
    }
  }

  Read(start: number, length: number, cmd: any) {
    let data = null;
    if (start >= 0 && start + length + this._zeroOffset <= this._size && this.STATE_READY === this._state) {
      const blob = this._file.slice(start + this._zeroOffset, start + length + this._zeroOffset);
      this._reader = new FileReader();
      const self = this;
      this._reader.onload = (e: any) => {
        data = new Uint8Array(e.target.result);
        self._owner._SendData(data, data.length, true);
        self._owner._SetSenseKeys(0, 0, 0, 0);
        self._owner._CommandFinish(cmd);
      };
      // 文件读取错误时提示
      this._reader.onerror = (err: any) => {
        self.vm._client.showMessage(
          'REMOTE_FILE_ERROR_TIP',
          'ReadFileFailedDialog',
          'HOME_PERFWARNING',
          'warning',
          true
        );
        self.vm._Reset();
      };
      this._reader.readAsArrayBuffer(blob);
    } else {
      this._owner._SetSenseKeys(5, 0x21, 0, 0);
      this._owner._CommandFinish(cmd);
    }
  }

  TestUnitReady() {
    let curState = this.STATE_READY;
    if (this._size < 0) {
      if (this.STATE_READY === this._state) {
        curState = this.STATE_CHANGE;
      } else if (this.STATE_CHANGE === this._state || this.STATE_NOTPRESENT === this._state) {
        curState = this.STATE_NOTPRESENT;
      }
    } else {
      if (this.STATE_NOTPRESENT === this._state) {
        curState = this.STATE_CHANGE;
      } else {
        curState = this.STATE_READY;
      }
    }
    this._state = curState;
    return curState;
  }

  SetDeviceState(state: number) {
    this._state = state;
  }
}
